William murphy



( No Model.)

W. MURPHY.

V CANVAS STRETOHER FOR PICTURE FRAMES.

No. 897,139. Patented Feb. 5, 1889.

lJNiTEo STATES PATENT EErcE.

\VI'LIIIAM MURPHY, OF ST. JOHN, NEIV BRUNSIVIOK, CANADA.

CANVAS-STRETCHER FOR PICTU RE-FRAM ES.

SPECIFICATION forming part of Letters Patent No. 397,139, dated February 5, 1889.

Application filed March 26, 1888.

To (LZZ whom it may concern.-

.leit known that I, \VILLIAM MURPHY, a citizenof the Dominion of Canada, residing at St. John, in the county of St. John and Province of New Brunswick, Canada, have invented certain new and useful Improvements in Can-= vas- Stretchers for Picture-Frames; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of this invention is to provide means for spreading picture-frames at the corners thereof in order to stretch the canvas thereon without allowing the parts of the frame to be displaced or tilted by the strain of the canvas. This object I attain by the construction and combination of parts here inafter set forth and claimed.

- In the accompanying drawings, Figure 1 represents a view in rear elevation of one corner of a canvas-holding frame provided with my invention and the canvas attached there to, the frame being slightly broken away to show the tongue in position. Fig. 2 represents the same in perspective, not broken away, but slightly spread, the canvas being raised. Fig. 3 represents in detail perspective the mitered and saw-kerfed end of one of the parts of the said frame. Fig. 4: represents a detail perspective view of the slightly-bent tongue, the bending being exaggerated to make it more obvious, and the slotted wedge which straddles it, the latter being separated to showthe slot. Fig. 5 represents a vertical section obliquely through the corner when the frame is lying flat.

Aiidesignat es the canvas, and B and C represent contiguous parts of a pictureframe forming one corner, and having their ends mitered, as usual, to fit thereat. The canvas is attached, as usual, by making it overlap the outer faces of these parts B and tacking it thereon. In each of the mitered faces a sawkerf, Z), is made at right angles to the said face, the saw-kerl' running lengthwise of said face and down the middle of it.

1) designates a tongue or holding-plate of sheet metal, having arms or teeth (1 extending laterally with respect to the body of theplate and obliquely inward with respect to the frame. These arms or teeth enter the saw- $erial No. 268,540. (No model.)

kerfs Z), and the body of the tongue or holding plate enters the said saw-kerfs likewise when the parts B and O of the frame are brought together. lVhen the frame is in its inost contracted shape, the initered ends touch each other and the tongue or holding-plate D is entirely embedded therein, except the upper corners, which are bent over slightly 011 the outer edges of the parts B and G; or, as in Fig. 1, only one of said upper corners maybe thus bent, the other being so shaped as to be entirely embedded.

The plate or tongue D is bent on its middle longitudinal line, so as to be very broadly V- shaped in cross-section, with a slight inclination from the middle to the edge. The object of this shape is to resist more effectually the tilting strain of the canvas on the parts B and C. For this purpose the tongue or plate D is inserted with the convexity outward, so that the strain of the canvas will tend to straighten, said tongue and will be resisted by the metal.

To spread the frame by separating the contiguous mitered faces of the parts B and C, I employ a wedge, E, which is pressed between the inner ends of said faces and slotted at e to straddle said plate or tongue. Each corner of the frame is provided with a tongue and a wedge constri'icted and combined as described, in order that the canvas may be stretched equally at all points and will lie smoothlyeverywhere. Of course other material may be substituted for canvas, and the frame may be used without any connection with pictures. Any flexible covering attached to it will be tightened by pressing the wedges in between the mitered faces of the frame, and the tongues will hold the parts of the latter against displacement. The wedges, being quite separable from the plates or tongues, may of course be withdrawn. and replaced without interfering with the position of the tongues or plates in any way. These stretching and holding devices do not require any modification of the ordinary frame beyond the sawkerfs. These last are not new, having been heretofore used with slotted holding plates or tongues which receive pins or studs in their slots, each plate being moreover in one piece with the corresponding wedge, in some instances at least.

Having thus described my invention, what I claim as new, and desire to secure by Letters I eral arms or teeth (I, which enter said saw- Patent, is

1. A tongue or holding-plate, in combination with two contiguous parts of a frame, each part being saw-l; erl'ed to reeei ve one edge middle in line with their meeting 'l'aees, 'l'or 1he purpose set forth.

2. A tongue or holding-plate, l), m'nhled with oblique lateral teeth (I, in combination with the parts I L of a frame, having in iheir lllilitl'ed laeesl'he szuv-kerls I) to receive said Teeth, and the body ol said plate, Sllbhlillltially as set forth.

3. In eolnbinatimi with the parts 13 and of the frame niit'ered and saw-kerlfed, as described, the holding-plate or tongue 1), bent in the middle and arrzing'ed with the convex side outward, said tongue or plate having latkerlj's, for the purpose set forth.

4. The wedge E, having" slot P, in eonlbination with the tongue l), having'lateral ieelh (I, and the parts 13 of the frame, having sawof Said plate and the latter being bental; the kerjlfs b, all arranged and operatingsubstantially as set: forth.

5. In combination with two ((HlhlgllOllS parts of a l'rame havingeorresponding saw-lx'erfs in their faces, a metallie tongue fitting;- into said, SfldY-lifil'ffi, and a slotted wedge li t1 lug between said farm and straddling Raid tongue, sub slantially as set forth.

In teetiniony whereof I at'lix my signatu re in presence of two witneshes.

\VILLIAM MURPHY.

\Vitnesses:

GEoneE Il. BRLYEA, 1 1mm; AL WARD. 

